[Below is the original script. But a few changes may have been made during the recording of this audio podcast.]

The people of the world will drive some two billion cars by 2030, up from roughly 700 million today. One of the leading hopes for avoiding greenhouse gas overload from all those tailpipe emissions is electric cars.

From the Chevy Volt to the Tesla Roadster, cars that run on battery power rather than gasoline are fueling hopes for a cleaner transportation future. Even if we switched all U.S. cars to run on electricity from coal-fired power plants we'd emit less than we do now, according to a study from Pacific Northwest National Laboratory.

But, in terms of economics, are we trading peak oil for peak lithium? Lithium is, obviously, a primary component of the lithium ion batteries powering the first generation of electric cars. The bulk of it is found in Bolivia.

Even worse, according to some, most of these advanced batteries are made in Asia. In fact, General Motors selected a battery from Korean company LG over American start-up A123Systems for its initial Volt.

But GM, assuming it survives, is also investing in a battery manufacturing plant in Michigan and there are deposits of lithium in the U.S. as well. Peak lithium may yet become a concern but first there would have to be a lot more electric cars on the road.

—David Biello

60-Second Earth is a weekly podcast from Scientific American. Subscribe to this Podcast: RSS | iTunes

60-Second Earth is a weekly Podcast. Subscribe to this Podcast: RSS | iTunes